Image sensors using CMOS architecture, or CCD architecture, are known. For example, a CMOS active-pixel sensor (APS) typically includes an array of pixel sensors, where each pixel has a photodetector and an active amplifier. Such a CMOS image sensor is produced by a CMOS process. Electromagnetic radiation (EMR), such as visible light, impinging upon a pixel, is converted to electrons and sensed by the pixel. Circuitry next to each photodetector of a pixel converts the light energy to a voltage.
Image sensors are limited to sensing EMR within a wavelength band or bands, to which the pixel material is sensitive. For example, typical pixel sensors are made of silicon, and are sensitive to EMR wavelengths to which silicon is responsive. Sensing other wavelengths such as short-wave infrared (SWIR), mid-wave infrared (MWIR) or long-wave infrared (LWIR), is generally not possible with a silicon based CMOS image sensing array.